\ . . Figure 29. 



MUSSELS. 75 



shown in Figure 28. J The shell is thin and delicate, 

 and (you notice) that the umba. or shoulder, is not 

 quite at one end, as in the true mussel. 

 /Figure 29 shows the shape of)another 

 small mussel, which sometimes lives un- 

 der stones j f ' Its shell is full of wrinkles. 

 But the oddest of the whole family of 

 mussels is th Pea-pod Shell/shown in 

 Figure 30.y This mussel is not content 

 with fastening itself by threads, but it also bores 

 a deep hole into the very rock, creeping inside as 

 it grows, and leaving only a little opening for the 

 water to come and go. 



As the shell grows larger, the creature bores 

 deeper, and thus it passes its life safely, though 



how little 

 it knows 

 ( of what is 



re 80. going Qn 



in the great world ! Are you not thankful that you 

 are not a mussel? 



BLACKBOARD WORDS. 



byssus (bis'-sus). A group of threads which hold a shell to a 



rock. 



securest (se-kur'est). In the safest and surest manner. 

 delicious (de-lish'us). Having a fine flavor. 

 harpoon (har-pobn'). A spear to which a cord is attached. 



It is used for catching whales and seals. 



